Broaching attachment



1927. Oct c. c. HANSEN BROACHING ATTACHMENT 2 Shaaeizs-Sheet Filed Sept.1926 INVEN TOR.

CZQ'Z'IML awsezz.

HIS ATTVEY Patented Oct. 18, 1927.

UNITED STATES r 1,646,090 PATENT OFFICE.

CHARLES C. HANSEN, OF EASTON, PENNSYLVANIA, AS SIGNOB '10INGEBBOLIa-RLNID COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OFNEW JERSEY. I

BBOACHING ATTACHMENT.

Application filed September 23, 1926. Serial 1T0. 137,801.

This invention relates to rock drills, but more particularly to abreaching attachment for fluid actuated rock drills of the hammer type.

The objects of the invention are to enable a broaching tool to besuitably guided during the broaching operation, to facilitate theinsertion of the attachment into the tool and the removal therefrom, andto render the attachment capable of accommodating different types ofbroaching tools.

Other objects will appear hereinafter.

The invention consists of the combination of elements, features ofconstruction, and an rangement of parts substantially as hereinafterdescribed and more particularly pointed out in the appended claim andillustrated in the accompanying drawings, in wh1ch Figure 1 is anelevation in section of the front end of a rock drill equipped with abroaching attachment constructed in accordance with the practice of theinvention,

Figure 2 is a side view of the attachment partly broken away and partlyin section illustrating the manner in which the broaching attachment maybe secured to the cylinder of the rock drill,

Figure 3 is a transverse view taken through Figure 1 on the line 3-3looklng in the direction of the arrows,

Figure 4 is a similar view taken through Figure 2 on the line 44,

Figure 5 is a view similar to Figure 1 illustrating the manner in whicha fiat rectangular broaching tool having a rectangular head may besupported by the attachment, and

Figure 6 is a view similar to Figures 1 and 5 showing the manner inwhich a round headed broaching tool is supported by the attachment.

Referring to the drawings, the invention is shown embodied in a rockdrill in which only a front portion of a cylinder A is shown. Within thecylinder A is a reciprocatory hammer piston B adapt-ed to deliver blowsto an anvil block G. A front cylinder washer D at the front end ofthecylinder forms a closure therefor and also acts as a guide for the anvilblock C.

The attachment or front head E is supported by the cylinder A andpreferably secured thereto by means of bolts F which extend throughflanges G and H of the c linder A and the front cylinder washerrespectively and through an end wall J of the front head E, nuts K beingprovided for the bolts F for clamping the cylinder and the attachmentsecurely together. In the present instance, the attachment E has an inteal side wall L and has end walls 0 secure to the inner face of the wallL by bolts or screws P, thus leaving one side of the attachment open asat Q.

Adjacent that end of the attachment wh ch 1s secured to the front"cylinder washer D is formed a lug R which acts as a bearmg for a cover Sadapted to lie against the edges of the end walls 0 and has rearwardlyextending arms T which bear against the ends of the lugs R. Apertures Uare formed through the lug R and through the arms T for the reception ofa pin V which acts as a pivot for the cover S. In this way is formed aclosure for the open side Q for the attachment E.

Any suitable means may be provided for clamping the cover S securely inoperative position. In the present instance I-bolts W pivoted to thewall L extend through slots X in the cover S and in the side walls 0 andare provided with nuts Y which may be turned against the cover S aftersaid cover has been closed.

Disposed on the inner surfaces of the wall L and the cover S are cheekplates Z of preferably the same width as the 's ace between the endwalls 0. These chee plates are spaced with respect to each other to forma guideway b therebetween and are preferably secured to the wall L andthe cover S by means of bolts 0. In order to protect the bolts 0 againstexcessive strain caused by occasional impact of the anvil block Cagainst the cheek plates, the cheek plates are provided with transversekeys or tongues d which extend into slots 6.

The guideway b as formed by the end walls 0 and the inner surfaces ofthe cheek plates Z is of rectangular cross sectional area 1 adapted moreparticularly for accommodating and loosely guiding flat rectangularbroaching tools 7 of the type illustrated in Figure 5. As is well known,there are a variety of broaching tools of different designs particularlywith respect to the shank, a few of these types being illustrated in thedrawings. The broaching tool 9 illustrated in Figures 1 to 4 inclusiveis of a well known type in which the body portion h is of flatrectangular cross sectional area and the shank of which ma be either ofhexagonal or cylindrical s ape. In order to render the presentattachment capable of accommodating tools of this type, longitudinalgrooves 70 are formed on the inner surfaes of the cheek late Z for thereception of a shank o o the broaching tool g. These grooves 70 mayextend from the rearward end of the cheek plates to recesses p formednear the front ends of the cheek plates and into which recesses maextend a collar 9 carried by the tool g. T e recesses p are of suchlength as to permlt a considerable range of movement in a. longitudinaldirection of thetool g and the ends of the recesses 39 are adapted tocooperate with the collar 9 for limitmg the movement of the tool withrespect to the cheek plates.

Means are also provided on the cheek lates for preventing ejection ofthetool f illustrated in Figure 5. To this end shoulders 1' are formedacross the inner surfaces of the cheek plates Z to cooperate withshoulders 8 formed on the rearward end of the tool f.

In Figure 6 is illustrated a tool t having a rectangular body portionand carrying at its rearward end a c lindrical head it against which theblows o the anvil block C are delivered. In order to prevent ejection ofthis type of tool from the attachment, arcuate recesses '11 are formedin the rearward end of the cheek plates Z and -the end walls w of theserecesses 12 act as stops for the head a.

In ractice whenever it is desired to change broaching tools, the nuts Yon the bolts W may be partly unscrewed to permit the bolts to be rockedout of the slot X. The cover S may then be oscillated about its pivot asillustrated by the dot and dash lines in Figure 1 and the broaching toolmay be removed from the attachment. After another tool has been insertedin. the attachment the cover 5 may again be clamped to the side of theattachment.

The present invention is not limited in its use to one particular typeof broaching tool but will accommodate broaching tools of differentdesigns. This is particularly desirable in broaching operations in whichvarious types of broaching tools are in use and will eliminate theexpense of providing a separate broaching attachment suitable for eachparticular ty of broaching tool. A further desirable ligature of thisinvention is, that owing to the manner in which the one side of thecover S is pivoted to the attachment, very little time is required tochange the broaching tool.

I claim:

In a. broaching attachment adapted to be secured to the cylinder of arock drill, the combination of a front head having an open side, a coverpivoted to the front head forming a closure for the open side, cheekplates secured to the front head and the cover spaced to form arectangular uideway Ior loosely guiding a broaching tool, said checkplates having recesses in their inner surfaces near the front end of theguideway to receive a broaching steel collar, said check plates alsohaving longitudinal grooves in their in ner surfaces extending from therecesses to the rearward ends of the cheek plates for the reception of abroaching tool shank, and I-bolts pivoted to the front head for clampingthe cover to the front head.

In testimony whereof I have signed this specification.

CHARLES C. HANSEN.

